How many movies have Aarre Koivisto and Impi Aro collaborated on?

They have worked on 4 movies together! Their first movie together was Pikku Ilona ja hänen karitsansa (1957) while their highest rated movie together was Pekka ja Pätkä miljonääreinä (1958). They have not worked together since Pekka ja Pätkä mestarimaalareina (1959). They are most known for their comedy films together.